1. Field
Methods and apparatuses consistent with the exemplary embodiments relate to an antenna and emission filter. More particularly, the exemplary embodiments relate to an antenna and emission filter configured to reduce a surface wave.
2. Description of the Prior Art
The biggest issue in developing an antenna is to reduce the side lobe and thus maximize the main lobe, which relates to improving the performance of the antenna. In particular, the surface wave which occurs at the edge side of an array antenna functions as a side lobe that deteriorates the performance of the antenna.
To this end, in the past, a method of amplitude tapering has been used. This method increases the main lobe by adjusting the amplitude of the feeding signal of an array antenna. However, such a method requires controlling the gain regarding the PA (Power Amplifier) and LNA (Low Noise Amplifier) connected to the antenna. Therefore, there was a problem relating to increased power consumption.
There was also a method of increasing the main lobe by adjusting the distance between each antenna element of an array antenna. However, it is very difficult to appropriately adjust the distance between each antenna element. In addition, when the distance between each antenna element increases, an Aliasing effect may occur where it becomes difficult to distinguish between the main lobe and the side lobe, and when the distance between each antenna element decreases, a Coupling effect may occur where interruptions occur between neighboring antennas.